Inertia sliding type internal combustion engine starter

ABSTRACT

An inertia sliding type internal combustion engine starter having a rotary shaft upon which is located a driving plate, the two elements being interengaged via helical splines. A second plate is driven by the first plate, the second driven plate also interengaging a pinion via ratchet gear teeth. Rotation of the rotary shaft rotates and translates the various components to their starter position, the pinion engaging an engine ring gear to attain starting. If starting is incomplete, the inertia of the elements maintain such in their starter positions thus preventing the phenomenon of earlier retreat.

United States Patent 1 Matsumoto 1 INERTIA' SLIDING TYPE INTERNAL COMBUSTION ENGINE STARTER [75] Inventor: Tsuyoshi Matsumoto, l-Iimeji, Japan [73] Assignee: Mitsubishi Denki Kabushiki Kaisha,

Tokyo, Japan 22 Filed: Sept. 28, 1972 [21] Appl.No.:293,000

[30] Foreign Application Priority Data Jan. 25, 1972 Japan 47/10567 52 US. Cl 74/7 R [51] Int. Cl. F02n 11/00 [158] Field of Search -74/7 R, 7 A, 7 C; 192/42 [56] References Cited UNITED STATES PATENTS 2,455,328 11/1948 Buxton 74/7 A X 3,176,525 4/1965 Rose 74/7 R 1,330,567 2/1920 Woolson 74/7 X '[111 3,788,150 Jan. 29, 1974 2,569,267 9/1951 Tobias... 74/7 R 3,071,013 1/1963, Antonidis et a1 3,630,092 12/1971 Matsumoto et a]. 74/7 R Primary Examiner-Allan D. Herrmann I Attorney, Agent, or Firm-Oblon, Fisher, Spivak, Mc- Clelland & Maier [5 7] ABSTRACT An inertia sliding type internal combustion engine starter having a rotary shaft upon which is located a driving plate, the two elements being intere'ngaged via helical splines. A second plate is driven by the first plate, the second driven plate also interengaging a pinion via ratchet gear teeth. Rotation of the rotary shaft rotates and translates the various components to their starter position, the pinion engaging an engine ring gear to attain starting. If starting is incomplete, the in- 9 ertia of the elements maintain such in-their starter positions thus preventing the phenomenon of earlier retreat.

3 Claims, 3 Drawing F ignres INERTIA SLIDING TYPE INTERNAL COMBUSTION ENGINE STARTER BACKGROUND OF THE INVENTION 1. Field Of The Invention: v

The present invention relates generally to an engine starter of the Bendix type, wherein a pinion is caused to slide by the inertia of the pinion itself to interlock with an engine ring gear, and more particularly, it relates to an improved engine starter wherein return of the pinion after an incomplete starting period, such as often occurs in such structure, is prevented.

2. Description Of The Prior Art:

A conventional type premature retum-preventing device is disclosed in Japanese Patent Publication No. 9921 1965 and Japanese Utility Model Publication No. 2409/1966, 'wherein a groove is formed at the crest of a helical spline in the outer periphery of a screw sleeve and a return-stopper mounted to a pinion which is spline-fitted to the outer periphery of the sleeve is fitted to the groove at the time interlocking the pinion to the ring gear in order to prevent a premature return thereof. I

In such conventional devices, the return-stopper usually was pressed on the outer periphery of the sleeve by a spring. When the sleeve and the pinion were relatively moved by actuation of the starter, the stopper is slidably moved on the spline of the periphery of the sleeve. Accordingly, the friction experienced is quite severe and movement of the pinion has not been speedy because of the sliding friction, whereby starting of the engine has been disturbed.

Moreover, because of the complicated processing and assembly and theexpense thereof, a centrifugal stopper mechanism comprising a stopper and a spring detecting thenumber of rotations by centrifugal force has been fitted to the member directly contributing to interlock the ring gear of the direct engine with the pinion and the sleeve.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an engine starter having simple structure and an accurate mode of operation without the abovementioned disadvantages,

Another object of the present invention is to provide an engine starter wherein a ratchet assembly is provided between the pinion and .the driving assembly so that the structure is quite simple, the operation is accurate, and the reliability of the starter is improved.

-Still another object of the present invention is to provide an engine starter which is easy to manufacture due to its design which facilitates easy processing and assembly, and which will greatly reduce such costs of systems manufacture.

Yet another object of the present invention is to provide an engine starter which will prevent the phenomenon of earlier retreat by means which will not interfere with the starting procedure and which will render such procedure more accurate.

The foregoing objectives are achieved according to this invention through the provisionof an engine starter having a rotary shaft with a helical spline upon its peripheral surface, and a driving plate mounted upon the rotary shaft having a mating helical spline. A driven plate and pinion are also provided, the driven plate and driving plate being interconnected by a flanged projection and groove assemblies, while the driven plate and pinion are interconnected via ratchet gear teeth. Rotation of the rotary shaft by a starter motor causes the various components to rotate and translate relative to the rotary shaft against the action of a coil spring, the pinion engaging an engine ring gear to attain starting. If starting is incomplete, the inertia of the various components maintains and retains such in their translated starter positions against the return action of the spring.

BRIEF DESCRIPTION OF THE DRAWINGS Various other objects, features, and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

FIG. 1 is a partial sectional view of an engine starter constructed in accordance with this invention, at the commencement'of the starting operation; 7

FIG. 2 is a sectional view of an engine starter as illustrated in FIG. 1, taken along the line IIII of FIG. I;

and

FIG. 3 is a partial sectional vi'ew of an engine starter as illustrated in FIG. 1, illustrating the cooperative parts during operation of the device. I

DETAILED DESCRIPTIONv OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and more particularly to FIGS. 1 and 2 thereof, a rotary shaft 1 of the starting motor, which is not shown in the drawings, has a-male helical spline 2 formed upon its outer peripheral surface, while an annular driving plate 3 has, upon its inner peripheral surface, a female helicalspline 4 for mating with the helical spline 2, and radially extending projections 5 for transmitting and transforming rotary motion into translative motion, in conjunction with splines 2 and 4, as will be apparent hereinafter.-

Buffers 6, which may be made of an elastomer, such as, for example, rubber, are provided for buffering propulsion forces whichare generated during'the engine startingperiod, and are disposed between projections 5 and an annular driven plate 7, being held in such location and in a preliminarily compressed state by caulked portions 9 of plate 7 which abut or overlap plate 3. Driven plate 7 is in turn provided with a plurality of grooves or recesses 8 for receiving projections 5 of driving plate 3, whereby the rotary movement impressed upon driving plate 3 by rotary shaft 1 is enabled to be transmitted to driven plate 7.

In order to further transmit the rotary motion impressed upon plate 7, the latter is additionally equipped with ratchet gear teeth 10, which may be formed by various metal operations, such asfor example, pressing. An annular pinion 11, for driving the engine, is likewise provided with ratchet gear teeth 12 for interlocking engagement with the teeth 10, both sets of teeth being formed upon oppositely disposed side surfaces or faces of their respective members. It is noted that both sets of teeth 10 and 12 are formed so as to enable the transmission of the rotary movement in one direction only, i.e., from plate 7 to pinion ll.

An annular groove 13, disposed in the other side face or surface of pinion 11, houses one end of a coil spring 14 which is provided for returning pinion 11 to its orginal position upon completion of the starting operation, while an annular pinion stopper 15 houses the other end of spring 14. A retaining ring 16 locks stopper 15 in a pre-determined position relative to shaft 1, while a conventional engine ring gear 17 is provided for engagement with starter pinion ll.

Still referring to FIGS. 1 and 2, the operation of the invention will now be described. The engine starter switch, not shown in the drawing, is closed in order to feed power to the starter motor. Consequently, when the rotary shaft 1 is rotated, the driving plate 3, the buffers 6, the driven plate 7, and the pinion 11 are all interengaged via splines 2 and 4, projections 5, and gear teeth and 12, and all have zero kinetic energy as each element was initially at rest. Hence, the teeth 10 and '12 of the ratchet assembly will be impulsively connected at their edge surfaces, while the driven plate 7 will similarly be suddenlyimpressed by an impulsive force due to the impulsive connection with driving plate 3 via projections 5. However, the impulsive force will be buffered by the buffers 6, whereby the impulsive force transmitted to the pinion 11 from plate 7, via teeth 10 and 12, will be diminished somewhat, or at least is not as great as it would be in the absence of buffers 6. The condition of such impulsive connection of the teeth 10 and 12 is subsequently changed and relaxed or diminished a short time after the rotary shaft 1 has been rotated by the starting motor, such condition permitting the pinion 11 to be subsequently easily interlocked with the ring gear 17. Such occurs upon further rotation of shaft 1 which, in association with 1 splines 2 and 4, causes driving plate 3, with its interlocked driven plate 7 and pinion 11 to be translated along shaft 1 from its position disclosed in FIG. 1 to that disclosed in FIG. 3.

Turning now to H6. 3, the operative condition of the starter is disclosed, wherein the rotary driving effect of the rotary shaft 1 forces driving plate 3 to rotate and translate along shaft 1 per splines 2 and 4 so as to compress coil spring 14 and the buffers 6, whereby the deflection of I1 is attained and the load upon the motor is lightened.

It is noted that in those instances where incomplete starting has occurred, the rotary driving effect of the engine is terminated and with conventional starters pinion ll is driven to its normal pre-start position, disen gaged from ring gearl7. This is the phenomenon of pre-mature or earlier retreat. Such occurs due to the action of coil spring 14 in conjunction with splines 2 and 4. However, the rotary driving effort transmitted from the pinion 11 to the driven plate 7 during such return, per the free rotary action of the ratchet gear teeth 10 and 12 is only a small effort, dictated by the spring pressure of the return spring 14 and the inclined angle of the ratchet teeth l0, 12, when compared to the iner- 4 tia of the driven plate 7, the buffers 6, and the driving plate 3. As such inertia force is substantially greater than the return force present, it is consequently seen that the presence of such inertia prevents the abovementioned earlier retreat phenomenon from occurring, whereby the engine is in a position for being accurately started per a subsequent attempt by the starter mechanism.

Thus, it may be seen that the engine starter of the present invention has important advantages over the known prior art structures in that the phenomenon of earlier retreat is prevented, yet such is accomplished by means which do not interfere with the starter operation, the means utilized thereby facilitating accurate starter operation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood, therefore, that within the scope of the appended claims the present invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An inertia sliding type internal combustion engine starter comprising:

a rotary shaft;

a driving plate connected to said rotary shaft via helical splines;

a driven plate connected to said driving plate so as to be translated in an axial direction;

an elastic material disposed between said plates;

said driving plate, said driven plate and said elastic material moving in unison and having a predetermined inertia prior to starting of said internal combustion engine; i

a pinion freely mounted upon said rotary shaft for interengagement with an engine ring gear;

a ratchet formed between said driven plate and said pinion which transmits rotary motion only in a direction leading from said driven plate to said pinion; and,

energy storage means engaging said pinion for biasing said pinion toward said driven plate,

said energy storage means constructed to provide a biasing force insufficient to overcome said predetermined inertia.

2. An inertia sliding type internal combustion engine starter as set forth in claim 1, wherein said ratchet comprises a first set of ratchet teeth formed upon the side surface of the driven plate facing said pinion, and a second set of ratchet teeth formedupon the side surface of said pinion facing said driven plate, so as to interlock with said first set of ratchet teeth.

3. An inertia sliding type internal combustion engine starter as set forth in claim 1, wherein:

said energy storage means comprises a coil spring po-' sitioned about said rotary shaft. 

1. An inertia sliding type internal combustion engine starter comprising: a rotary shaft; a driving plate connected to said rotary shaft via helical splines; a driven plate connected to said driving plate so as to be translated in an axial direction; an elastic material disposed between said plates; said driving plate, said driven plate and said elastic material moving in unison and having a predetermined inertia prior to starting of said internal combustion engine; a pinion freely mounted upon said rotary shaft for interengagement with an engine ring gear; a ratchet formed between said driven plate and said pinion which transmits rotary motion only in a direction leading from said driven plate to said pinion; and, energy storage means engaging said pinion for biasing said pinion toward said driven plate, said energy storage means constructed to provide a biasing force insufficient to overcome said predetermined inertia.
 2. An inertia sliding type internal combustion engine starter as set forth in claim 1, wherein said ratchet comprises a first set of ratchet teeth formed upon the side surface of the driven plate facing said pinion, and a second set of ratchet teeth formed upon the side surface of said pinion facing said driven plate, so as to interlock with said first set of ratchet teeth.
 3. An inertia sliding type internal combustion engine starter as set forth in claim 1, wherein: said energy storage means comprises a coil spring positioned about said rotary shaft. 